Improvement in lifting-jacks



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PATENT v ,OFICE.

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Specification 'forming part of Letters PatentNo. 35.3354., dated May 26,1863.

Tc all whom it may concern.

'Be'it'lnown that I, JEREMrAH Coon, of Palmersville, in thecounty oiAllegheny and 'State of Pennsylvania, have invented a new and ImprovedHcisting-Jack; and I do herebreadth, is secured a` 'strong standard, B,(shownin section in Fig. 1,)'whichmay be made of pieces of ordinarytimberor scan tl in g,nailed or bolted together.

cram-bar is providedl withsuitable notches,

`c c, for adjustment, in connection with a leverpawl ordetent, E,pivoted Yat tin one side of the standard. The inner upper extremity orclaw e of this'detent is held into the notches c c ot' the fulcrum-barby a spring, `s, or its equivalent, land it i`s moved and held away fromthe notches'at any/time by pushing inward the projecting lower end, f,of the detent.'

To the4 upper -end of the fulcrum-bar G the .hoisting-lever D is`pivoted at d 4suiicently neartheend where-the weight is tobe lifted toyproduce the requisite leverage. The fulcrum can, of course, be adjustedby lhaving at' set of several pivot-holes inV the lever;

0n" the front 'edge' ,l of the standard B is ""a ratcl, G,the notches gg of which hook down'- w'ardand correspond nearly indista-nce apart withthat of the ratch-teeth c c of the fulcrum- Y bar.v OThen from the leverD, in front, of the ,fulcrum d, extends-a catch-hook or stirrup,1:'l,down so as tocatch intothe teeth of the ratch A Y G. A spring, h,serves" to draw the catch-h In this standard is a verf tical aperture,b, from top to bottom, in which slides an adjustable fulcrurnbar, U. Theful- October, 1862. Y .;v

' JEREMIH COOK. [Ls] into the notches of the lratch. T

The use and advantages of this improved hoistin g-j ack are too obviousto need much explanation. When any Weight or object is to be raised bylever-power thefulcrurn bar C is lowered to its'proper height byreleasing the detent E. Then the lever D is inserted and the object israised as far as a` single depres `sion ofthe lever-handle will effectit. The

catclrhool; H immediately catches oneof the teethI g/ g of the ratch Gand holds the ,lever down till the object ispropped. kThen the.caitnhnok,isrelemedxandithe.fnlcrumfber-Q is raised a notch in itsstandard -by simply-- lifting it, when the lever is ready to hoi-st theobject another notch in the same 'si-ay. Thus the operation isvcontinued till completed,

- The machine is not only eiective and convenient in operation, butexceedingly cheap, easily made, rendering it very desirable, especiallyfor farmers use.

There may be dierent ways of constructing the standard B and otherpartssuch :is makingl the fulcrumbar C Adouble and slide in grooves inthe opposite sides of the standard;

buts-these variations are not essentiah' There may be a stop, i', Fig.3, to prevent theful` cram-bar C from being drawn entirely out vot' fthe standard. g

What I claimas my invention, and desire.,.to.-.

secure luy-Letters Patent iss- Q The combinationetlJehook-catch H,ratch.

G, agd spring 71", with the lever D and notched fulcrumbar G,substantially as andfor/the 'purpose herein specied. 1 Y d The abovespecication'of my.improved'* hoisting-jack signed byv me this 28th'dayoti Witnesses:

' Al-rrrnmr 4LpNG, JonN. PALMER.

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